diff --git a/drivers/s390/char/vmur.h b/drivers/s390/char/vmur.h
index 2b3c564..fa95964 100644
--- a/drivers/s390/char/vmur.h
+++ b/drivers/s390/char/vmur.h
@@ -70,6 +70,7 @@
 	size_t reclen;			/* Record length for *write* CCWs */
 	int class;			/* VM device class */
 	int io_request_rc;		/* return code from I/O request */
+	atomic_t ref_count;		/* reference counter */
 };
 
 /*